diff --git a/components/schemas/environments/services/discovery/DiscoveryConfig.yml b/components/schemas/environments/services/discovery/DiscoveryConfig.yml
index cc0ebab2..c4d01b68 100644
--- a/components/schemas/environments/services/discovery/DiscoveryConfig.yml
+++ b/components/schemas/environments/services/discovery/DiscoveryConfig.yml
@@ -6,11 +6,6 @@ properties:
     anyOf:
       - $ref: ../../../Duration.yml
       - type: "null"
-  dual_stack_legacy:
-    description: When enabled, discovery will return both IPv6 and IPv4 when in legacy mode.  Otherwise, only IPv4 will be returned.
-    anyOf:
-      - type: boolean
-      - type: "null"
   hosts:
     description: A mapping of hostnames to IP addresses for custom internal resolutions. Acts as a custom /etc/resolv.conf file that works environment wide.
     oneOf:
@@ -40,3 +35,18 @@ properties:
         items:
           type: string
       - type: "null"
+  dual_stack_legacy:
+    description: When enabled, discovery will return both IPv6 and IPv4 when in legacy mode.  Otherwise, only IPv4 will be returned.
+    anyOf:
+      - type: boolean
+      - type: "null"
+  external_resolution:
+    anyOf:
+      - type: object
+        required:
+          - preference
+        properties:
+          preference:
+            type: string
+            enum: [default, ipv4, ipv6]
+      - type: "null"
diff --git a/stackspec/schema/services/discovery/StackSpecDiscoveryConfig.yml b/stackspec/schema/services/discovery/StackSpecDiscoveryConfig.yml
index 53935298..d4a2292e 100644
--- a/stackspec/schema/services/discovery/StackSpecDiscoveryConfig.yml
+++ b/stackspec/schema/services/discovery/StackSpecDiscoveryConfig.yml
@@ -6,12 +6,6 @@ properties:
       - $ref: ../../../../components/schemas/Duration.yml
       - $ref: ../../StackVariable.yml
       - type: "null"
-  dual_stack_legacy:
-    description: When enabled, discovery will return both IPv6 and IPv4 when in legacy mode.  Otherwise, only IPv4 will be returned.
-    anyOf:
-      - type: boolean
-      - $ref: ../../StackVariable.yml
-      - type: "null"
   hosts:
     description: A custom mapping of hosts - for forced resolution of specific IPs for a domain.
     oneOf:
@@ -46,3 +40,20 @@ properties:
           type: string
       - $ref: ../../StackVariable.yml
       - type: "null"
+  dual_stack_legacy:
+    description: When enabled, discovery will return both IPv6 and IPv4 when in legacy mode.  Otherwise, only IPv4 will be returned.
+    anyOf:
+      - type: boolean
+      - $ref: ../../StackVariable.yml
+      - type: "null"
+  external_resolution:
+    anyOf:
+      - type: object
+        required:
+          - preference
+        properties:
+          preference:
+            type: string
+            enum: [default, ipv4, ipv6]
+      - $ref: ../../StackVariable.yml
+      - type: "null"